Various devices and methods for stabilizing bony segments have been used for many years. For example, the fracture of an elongated bone, such as a femur or humerus, can be stabilized by securing a plate to the fractured bone across the fracture. The plate extends across the fractured area and thus stabilizes the fractured components of the bones relative to one another in a desired position. When the fracture heals, the plate can be removed or left in place, depending on the type of plate that is used.
Another type of stabilization technique uses one or more elongated rods extending between components of a bony segment and secured to the bony segment to stabilize the components relative to one another. The components of the bony segment are exposed and one or more bone engaging fasteners are placed into each component. The elongated rod is then secured to the bone engaging fasteners in order to stabilize the components of the bony segment.
One problem associated with the above described stabilization structures is that the skin and tissue surrounding the surgical site must be cut, removed, and/or repositioned in order for the surgeon to access the location where the stabilization device is to be installed. This repositioning of tissue causes trauma, damage, and scarring to the tissue. There are also risks that the tissue will become infected and that a long recovery time will be required after surgery for the tissue to heal.
Minimally invasive surgical techniques are particularly desirable in, for example, spinal and neurosurgical applications because of the need for access to locations within the body and the potential trauma to vital intervening tissues. The development of percutaneous minimally invasive spinal procedures has yielded a major improvement in reducing trauma, recovery time and post-operative pain. The benefits of minimally invasive techniques have also found application in surgeries for other locations in the body where it is desirable to minimize tissue disruption.
One potential disadvantage associated with minimally invasive techniques is that the tissue can obstruct access and visualization of the implantation location for an implant in the body of the patient. Accordingly, the optimally sized implant for implantation between anchors or other structures in the patient may not be readily determinable. While minimally invasive techniques have yielded benefits, there remains a need for instruments and methods that facilitate application of minimally invasive procedures during surgery.